If ever a photograph needed a soundtrack, this one does. Where are the cannonades from the ships, the sniper fire, the groans of the wounded? But on second thoughts, perhaps it's the silence that makes the image so plaintive, such a candid glimpse of the waste and mess of war. Two great film directors – Grigori Kozintsev in King Lear, Akira Kurosawa in Ran – transform battles into tragedies by simply turning the sound off: without the yelling of troops and the discharge of weapons, what we watch suddenly becomes absurd, a spectacle of pointless carnage.

The stasis of the image becomes an extra source of discomfort, even of panic: why does the photograph hold the figures in place, when they need to run for cover? A third absence matches the mournful quiet and the fixity that makes these men targets. The scene is bled of colour (which means, mercifully, that we see no blood). Ironically, the setting is White Beach, nicknamed by the allied commanders when marking out assault sectors near Bernières-sur-Mer. The western beach was familiarly called Mike, and the one to the east, like a female companion, became Nan; it had three sections, Red, Green and White. The colours were abstract designations, because everything here is a smudged, murky grey, the colour of weary flesh and of soiled newsprint. Martha Gellhorn, Hemingway's wife, who travelled on a hospital ship in one of the D-Day convoys, reported that grey was the fleet's camouflage; her own ship was "snowy white, with a green line below the deck rail, and many bright new red crosses painted on the hull". The gaudy display made her floating emergency ward dangerously conspicuous.

What we have is a salvaged moment, snatched on the run. Yet in documenting the scrambled, stumbling confusion, the photographer stills life into a series of tableaux that look like quotations from religious art. The two soldiers who hold up a third, helping him to walk, might be staggering towards Calvary. One man kneels before another who wears a Red Cross armband: he has found a saviour. In the water, another kneeling man seems like a candidate for baptism – though is that a dead body behind him, lying on its side as if asleep? It decomposes into grey specks when we try to look closer: the image atomises and we watch one more anonymous casualty of war fading into non-existence.